1. Field of the Invention
This invention relates to a channel assigning system for an electronic musical instrument and more particularly, to an improved method of determining the channel assignment priority order.
2. Description of the Related Art
In a prior art channel assigning system, when, for example, a Key On event occurs in a keyboard of a electronic musical instrument, a check is made to determine whether a musical tone corresponding to a "key off" event exists among tones having respective channels assigned thereto. If a tone corresponding to a "key off" event does exists, a channel assigned to the tone corresponding to the new "key off" event is a channel that was assigned to the tone corresponding to the "key off" event.
In an improved channel assigning system, sequential "key on" and "key off" event order numbers of tones having respective channels assigned thereto are stored, and the channels are assigned in accordance with the sequential order numbers.
When a plurality of tones are produced simultaneously, some are very easily heard by the human ear when muted, but others are not. For example, when a plurality of low pitch tones are produced together with a high pitch tone, if the "key off" of the low pitch tone occurs earlier than the "key off" of the high pitch tones, usually the channel corresponding to the earlier "key off" high pitch tone will be assigned to a tone corresponding to a new "key off" event. However, if the sounding level the high pitch tone is not very different from the low pitch tones, the "key off" of the former is more easily heard by the human ear than the "key off" of the low pitch tones, and acoustically this produces a feeling of discomfort. This is true not only for the tone pitch but also for the timbre, speed and strength of a sounding operation, and the performance of a melody, chord and rhythm.